/*
  解析和匹配 Css 的选择器
  github：https://github.com/jin-yufeng/Parser
  docs：https://jin-yufeng.github.io/Parser
  author：JinYufeng
  update：2020/03/15
*/
var cfg = require('./config.js');

class CssHandler {
    constructor(tagStyle) {
        var styles = Object.assign({}, cfg.userAgentStyles);
        for (var item in tagStyle)
            styles[item] = (styles[item] ? styles[item] + ';' : '') + tagStyle[item];
        this.styles = styles;
    }

    getStyle = data => this.styles = new CssParser(data, this.styles).parse();

    match(name, attrs) {
        var tmp, matched = (tmp = this.styles[name]) ? tmp + ';' : '';
        if (attrs.class) {
            var items = attrs.class.split(' ');
            for (var i = 0, item; item = items[i]; i++)
                if (tmp = this.styles['.' + item])
                    matched += tmp + ';';
        }
        if (tmp = this.styles['#' + attrs.id])
            matched += tmp + ';';
        return matched;
    }
}

module.exports = CssHandler;

class CssParser {
    constructor(data, init) {
        this.data = data;
        this.floor = 0;
        this.i = 0;
        this.list = [];
        this.res = init;
        this.state = this.Space;
    }

    parse() {
        for (var c; c = this.data[this.i]; this.i++)
            this.state(c);
        return this.res;
    }

    section = () => this.data.substring(this.start, this.i);
    isLetter = c => (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');

    // 状态机
    Space(c) {
        if (c == '.' || c == '#' || this.isLetter(c)) {
            this.start = this.i;
            this.state = this.Name;
        } else if (c == '/' && this.data[this.i + 1] == '*')
            this.Comment();
        else if (!cfg.blankChar[c] && c != ';')
            this.state = this.Ignore;
    }

    Comment() {
        this.i = this.data.indexOf('*/', this.i) + 1;
        if (!this.i) this.i = this.data.length;
        this.state = this.Space;
    }

    Ignore(c) {
        if (c == '{') this.floor++;
        else if (c == '}' && !--this.floor) this.state = this.Space;
    }

    Name(c) {
        if (cfg.blankChar[c]) {
            this.list.push(this.section());
            this.state = this.NameSpace;
        } else if (c == '{') {
            this.list.push(this.section());
            this.Content();
        } else if (c == ',') {
            this.list.push(this.section());
            this.Comma();
        } else if (!this.isLetter(c) && (c < '0' || c > '9') && c != '-' && c != '_')
            this.state = this.Ignore;
    }

    NameSpace(c) {
        if (c == '{') this.Content();
        else if (c == ',') this.Comma();
        else if (!cfg.blankChar[c]) this.state = this.Ignore;
    }

    Comma() {
        while (cfg.blankChar[this.data[++this.i]]) ;
        if (this.data[this.i] == '{') this.Content();
        else {
            this.start = this.i--;
            this.state = this.Name;
        }
    }

    Content() {
        this.start = ++this.i;
        if ((this.i = this.data.indexOf('}', this.i)) == -1) this.i = this.data.length;
        var content = this.section();
        for (var i = 0, item; item = this.list[i++];)
            if (this.res[item]) this.res[item] += ';' + content;
            else this.res[item] = content;
        this.list = [];
        this.state = this.Space;
    }
}
